Influence of crystallite size on color properties and NIR reflectance of TiO2@NiTiO3 inorganic pigments

Crystallite size may significantly impact optical properties of inorganic pigments. However, limited studies have so far been reported in this area. In this work, TiO2@NiTiO3 complex pigments were synthesized by precipitation-calcination method. Results showed that the increase in calcination temperature led to the formation of TiO2@NiTiO3 pigments with crystallite sizes from 29 to 82.6 nm but similar morphologies and aggregate particle sizes (around 1 ?m). The yellow component (b*) significantly increased by 7 with crystallite size, but the integrated NIR reflectance decreased slightly (4.02%). Also, the characteristic absorption of NiTiO3 pigments in NIR region declined the integrated NIR reflectance values.

Automated summary

The crystallite size can significantly influence the optical properties of inorganic pigments, with larger sizes leading to increased yellow component and slightly decreased integrated NIR reflectance. The synthesis of TiO2@NiTiO3 complex pigments revealed that as the crystallite size increased, the optical properties of the pigments were affected, showing changes in both color and reflectance values in the NIR region.